Climate change and river basins

IPCC AR4

2009-07-27T18:07:00.000-07:00

I have downloaded the Synthesis and the first two volumes (Working Groups I and II) of the IPCC Fourth Assessment Report. There is a substantial chapter in Volume 2 about water. Of course it covers the whole planet, but it contains a lot of material that is relevant to our Chapter for the Basins' book.

I suggest that I email you a copy of the chapter (I have created all the cross links to make it easier to navigate). I further suggest that we use the structure of this chapter for our work, and I urge you to let me have material from your Basins set out in this structure.

Some of our colleagues have not signed up to the blog even though I have sent two invitations to do so. I'll send a personal email to them today to invite their participation.

Cheers.

Sahel nations may lose maize by 2050

2009-07-15T06:30:00.000-07:00

See Article.
Abstract of paper.

CIESIN report on CC and migration

2009-07-13T14:25:00.000-07:00

The Center for International Earth Science Information Network at the Earth Institute of Columbia University (CIESIN) have produced a report on the effects of climate change on migration of vulnerable people. The report includes a lot of data on likely effects of climate change on Himalayan glaciers and flows of the rivers that rise on the Himalayan plateau, runoff in Central America and Mexico, West Africa/Sahel, and sea-level rise in the Ganges, the Mekong, and the Nile deltas. It is a useful report for us to consider for the GCC chapter.
See Report.

The Vietnam Thanh Nien newspaper of 11 July reports on the Mekong bits of the CIESIN report. It seems to be an even-handed summary that is very well written.
See Article.

The CIESIN article is also the basis of an article in the Economist.
See Article.

2009-07-13T13:46:00.000-07:00

As a lazy blogger, I refer readers to an interesting debate on the reality of sustainable development that is proceeding in the Economist (link below). Climate change figures frequently in this debate because, to some, it illustrates the danger of unsustainable development. The moderator makes one of the best observations in his summing up and I quote this here

Another way of looking at things, though, is to ask what can be tolerated and fixed, and what is simply intolerable, because it is irreversible. Here, science can help at least to analyse the problem. ...Many natural systems can be pushed so far and no further. If pushed beyond a threshold, they will find a new equilibrium, and pushing them back whence they originally came will be hard indeed. (from Mr Geoff Carr).

I commend readers to visit the original if, for no other reason, because it is interesting to see how the protagonists (a lawyer and medical scientist) view the issues of sustainable development. See Economist debate on Sustainable Development here

Climate change, coffee and implications for basins

2009-07-13T07:01:00.000-07:00

I quote from CIAT's blog
"In Colombia alone, there are over half a million smallholder coffee farmers who depend on the crop. In Central America, coffee is the second greatest source of rural income for the 20 million-or-so farmers in the region. If you take into account the associated rural businesses that buy, transport, process and export the crop, you realise that coffee is a major contributor to GDP for most countries in the region."
"[CIAT] looked into the future of coffee production in Central America, to see what climate change has in store. The findings are shocking. For example, Nicaragua will lose half of its potential coffee-growing area if temperatures increase by 2 degrees C. That means a large proportion of the country’s GDP will be wiped out and 2.5 million rural coffee farmers will have to find an alternative means of feeding their children. And for all you coffee lovers out there, [CIAT found] the first thing to disappear is quality. So as the world acquires a taste for decent coffee, climate change will reduce significantly the global capacity to produce a quality cuppa. And that means higher prices for the consumers."
A further conclusion of the work is that, where it is feasible, coffee production will migrate uphill (2 degrees temperature increase implies about 350 m higher altitude) to sites that will have the same temperature regime as now. But in much of Central America, the higher areas are forested, which implies land clearing with important implications for ecological services.

Climate change and river discharge

2009-06-24T06:10:00.000-07:00

For a number of basins the annual discharge is a linear functionsuch as
discharge= total rainfall on the basin minus a large value

There is a zero discharge for about 700 mm mean rainfall over the Volta (and Chari) basins. A 10 % change in the rainfall leads to a 30 % change in discharge.
Have we got examples for other BFP basins ? Does it apply to wet basins?

3 themes of GCC in river basins

2009-06-22T15:51:00.000-07:00

It may be helpful to consider organizing thought around 3 major themes:

Changing climate, and impact on water balance
Impacts of climate change on agricultural systems
The dynamic response of systems to these changes

Any suggestions of additional themes or reorganization welcome

Welcome

2009-06-22T15:43:00.000-07:00

This blog has been set up to discuss aspects of climate change in river basins to help develop a forthcoming book chapter from the basin focal projects of the CPWF.

For more information about the basin focal projects, visit here.
For more information about the Challenge Program on Water and Food, visit here